Coal-mining machine



Aug. 12, 1947. I R. T. HAIR ET AL COAL-MINING MACHINE.

' Filed April 13, 1944 5 sheet et 1 [Al/5, 3,195.: Elam/2 Ale,

' Aug. 12, 1947. R. T. HAIR Er m. 2,425,468

COAL-MINING MACHINE k Filed Aprilfl13, 1944 5 Sheets-Sheet 2 MIL Elvis?F/u/Aeo 7: HA 1?,

CHARLES 5 445 1947- R. T. HAIR ET AL 2,425,468

COAL-MINING MACHINE Filed April 13, 1944 5 Sheets-Sheet 3 Aug. 12, 1947.R. 'r. HAIR ET AL COAL-MINING MACHINE Filed April 15, 1944 5Sheets-Sheet 4 Aug. 12, 1947. R. TJHAIR ETAL I COAL-MINING MACHINE Filed April 13, 1944 5 Sheets-Sheet 5 //v I/EA/TOBS: Flo-men 77 1/4/19,

CHARLES F. fiflLL,

1477-0 EA/Eh Patented Aug. 12, 1947 UNITED STATES PATENT OFFICECOAL-MININ G MACHINE Richard T. Hair and Charles F. Ball, Franklin, Pa.,assignors to Richard '1. Hair, Charles E. Hair, and Binkley Mining Co.of Indiana, a corporation of Indiana, collectively doing business asHydrabuster Company Application April 13, 1944, Serial No. 530,790

12 Claims. 1

This invention relates generally to machines particularly, though notexclusively, adapted for use in coal-mining.

It is common practice in present day coal-mining, so far as we areaware, to first form a kerf in the working face of the coal wall andthen to drill or otherwise produce a series of holes at suitableintervals in the face of the coal wall of a horizontal depthapproximately equal to that of the kerf. Such holes, it may be observed,are for the purpose of receiving blasting powder or other pressuredevices, which, on explosion or actuation, dislodge the coal by movingit toward the kerf.

Dislodging of the coal by blasting powder or by sudden applications ofcompressed air or gases is accompanied by danger to personnel, loss oftime, and, in some instances, economic loss by reason of undesirableexcess fragmentation of the coal.

Our invention hence has for its chief object the provision of a rapidmethod of dislodging coal by means of a hydraulic mechanism capable ofsaving miners from roof falls caused by the shock of a shatteringexplosion, such as caused by blasting methods, and also to eliminateexcessive fragmentation and dust, as well as danger from fumes,premature explosions, or flying gas cartridges.

United States Letters Patent Nos. 2,346,676, 2,346,677, 2,346,678, and2,346,679, all issued on April 18, 1944, to Charles Edwin Hair andRichard T. Hair, disclose articulated coal-mining machines of the fluidpressure type, and our present invention has more particularly to dowith, and has for an additional object the improvement generally of,coal-mining machines of such articulated fluid pressure type.

And with the above and other objects in View, our invention resides inthe novel features of form, construction, arrangement, and combinationof parts presently described and pointed out in the claims.

In the accompanying drawings (five sheets) Figure 1 is a plan View of acoal-mining machine constructed in accordance with and embodying ourpresent invention, the machine comprising a selected plurality of unitsfor insertion in a hole formed in the working face of a mine and movablerelatively to one another, but correlated for co-operativ action and theseveral pistons of the several units being in normal or retractedposition;

Figure 2 is a side elevational View of the machine likewise with theseveral pistons of the several units thereof in normal or retractedposition;

Figure 3 is a side elevational view of the machine with its tworight-hand units illustrated as out of alignment and with the pistons ofsuch units in fully and partially expanded or so-oalled abnormalposition, as in a coal dislodging or breaking-down operation;

Figures 4 and 5 are end views of the machine looking in the direction ofthe arrows 44 and 55, Figures 2 and 3, respectively;

Figure 6 is an enlarged transverse sectional View taken approximately onthe lines 66, Figure 3;

Figure 7 is a similar View taken approximately on the line 'l'--'l,Figure 2;

Figure 8 is likewise a similar View taken approximately on the line8--8, Figure 3;

Figure 9 is an enlarged detail sectional View taken approximately on theline 9-9, Figure 5, looking in the direction of the arrows;

Figure 10 is a longitudinal sectional view taken approximately on theline lill 0, Figure 9;

Figure 11 is a left-hand end view of the upper or so-called yoke or hoodof one of the units of the machine;

Figure 12 is an enlarged fragmental longitudinal vertical sectional viewof some of the yoke or hood members of the machine, illustrating theassociated ends of adjacent or contiguous members and indicatingportions of the power-elements for expanding the unit;

Figures 13 and 14 are transverse sectional views of the machine takenapproximately on the respective lines Ill-l3 and l4-i4, Figure 12;

Figure 15 is an inverted plan View of the hood or yoke member of one ofthe units of the machine;

Figure 16 is a side elevational View, partly broken away and in section,of the body or cylinder-block of one unit of the machine;

Figure 17 is, in effect, a horizontal section through the body orcylinder-block of Figure 16, but broken away intermediate its ends. topermit drawing to a larger scale and to include the 3 fluid-couplingblocks applied, respectively, to the right-hand end of the first unitand to the lefthand end of the last unit of the machine;

Figure 18 is a left-hand end view of the cylinder-block shown in Figure16;

Figures 19 and 20 are transverse vertical sections respectively takenapproximately on the lines I9I9 and 292B, Figures 16 and 17, but showingthe body-structure only and omitting the fluid-coupling blocks;

Figure 21 is a plan view of the fluid-coupling block at the right-handor front end of the machine;

Figure 22 is a side view, sectioned in part, of the portion of themachine or structure shown in Figure 21;

Figure 23 is an end view of the portion of the machine or structureshown in Figures 21 and 22;

Figure 2 1 is a plan view of the fluid closure block or member at therear or left-hand end of the machine;

Figure 25 is an enlarged transverse vertical sec tion takenapproximately on the line 25-925,v

Figure 6;

Figure 26 is a plan View of a hood of slightly modified form;

Figure 27 is a side elevational view thereof;

Figure 28 is a right end elevational view thereof;

and

Figure 29 is a View analogous to Figure 12, illustrating the modifiedhood arrangement.

Referring now more in detail and by reference characters to thedrawings, which illustrate a preferred embodiment of our invention, themachine, lbriefly outlined, comprises a front end unit A, a rear endunit B, a desired or selected number of intermediate units C, andpreferably front and rear fluid pressure supply and closure members Dand E, respectively, all pivotally or hingedly coupled end to end inintegrated articulate relation for insertion or disposition endwise in ahole, for example, in the working face of a coalbody. 7

Each such unit A, B, or C is suitably elongated and of selected heightand dimensions for strength and rigidity and includes, in turn, a bodyor base a and an upper or so-called hood or yoke-member 27, associatedWithwhich is a selected plurality of power elements or jacks eachcomprising a cylinder 0 opening to and upon the upper face of the blocka and a co-operating fluid pressure actuated piston d, the several pairsof cylinders and pistons being spaced longitudinally of the unit withthe axes of the cylinders and their cooperable pistons extending atright angles to the length of the unit.

Each cylinder 0 is recessed or otherwise suitably formed in the body orblock a, as perhaps best seen in Figure 16, the block or preferablyhaving a rounded or arcuate under face, as at I as best seen in Figures7 and 8.

Each piston dispreferably of the telescoping or double acting type forsecuring greater range of movement and comprises an outer hollow ortubular portion I having at its upper end an inwardly presented annularflange 2 and being annularly enlarged and thereby provided adjacent itslower end withan annular shoulder, as at3, for engagement with a ring 4thread-seated in the upper end of the cylinder-cavity 5 for limitingoutward or expanding movement of the piston-portion I with respect tothe cylinder 0. 'A piston-rod portion 6 is similarly enlarged andthereby provided at, its lower end with an an.- nular shoulder, as at I,for engaging the flange 2 for similarly limiting outward or expandingmovement of the rod 6 with respect to the tubular member I. It might behere mentioned that the cylinder 0 and the piston d are so relativelyproportioned and sized as to be completely nested when in contractedcondition, as best seen in Figures 4 and '7, and to have a stretch ofapproximately three inches when in fully expanded or extended condition,as best seen in Figure 5. At their respective lower ends, it may be alsohere mentioned, the piston-members I and 6 are annularly reduced, asbest seen in Figures 7 and 8, for accommodating suitable cylinder-wallengaging or sealing ring-assemblies 8, 8, preferably held in place bysuitable flanged caps 9, while the ring 4' and piston flange 2 arepreferably suitably provided with packing-members III, all forfacilitating proper piston reciprocation.

One or more of the power elements or jacks in each unit may be, it maybe here stated, arranged for application of suitable pressure fluidselectively to either side of the piston, so that the yoke orhood-member b may be forced not only to projected position, but also toretracted position, the latter facilitating the freeing of the machinefrom the walls of the drill-hole and dislodged coal. In the presentinstance, the several pistons of each unit are so arranged, the conduitsfor leading pressure fluid to the several cylinders c and pistons atbein presently fully described.

While the axis of each jack or co-operable cylinder 0 and piston d isfixed relatively to the block or base a, the; connection between eachpiston 11 and the yoke or hood I) of each unit is such as to permitrelative longitudinal and angular movement therebetween, as shown orindicated, for instance, in Figures 3, 7, 8, 10, and 12.

To provide for this movement of the hood or yoke b, each of thepistonrods 6 is provided at its outer end with a pillow-block II, theouter or upper face of which ha an arcuate contour longitudinally of theyoke 6 (Figures 8 and 9). A pillow-block I3 having an arcuate under'facefor mating with the arcuate outer face of the pillowblock II is seatedfor turning movement thereoni The pillow-block I3 have their outersurfaces V shaped keystone groove I2 which extends longi- V tudinally ofthe yoke Z).

From the foregoing construction, it is apparent that the interengagingmating arcuate faces of the pillows I I and the pillow-blocks I3 permitthe pistons d to tilt or turn in a plane extending longitudinally of theyoke b, while the blocksv I3 slide freely relatively to the yoke b asthe pistons 01 or the block a assume an angular position relatively tothe yoke b. In assembling a'hood or yoke 1) upon several pistons ofthe'particular unit, the blocks II and I3 are, disposed in co-operativeslidable relation, and a yoke or hood b then endwise slidably fittedupon the blocks I 3, the latter being accommodated in the groove I2.Hence, it may further be said here, the block or base-a of a-unit maymove or shift both with and relatively to its companion yoke or hood bin a coal dislodging operation, a lug I4, Figure 12, near .the righthandend of the yoke b and a detachable lockingof aunit in operativerelation, V

The body or. base membera of preferably each iv unit A, B, and,Cfisconstructed for connection at both endsv to an" adjoining member aor to the end-members D, E t'hrough overlapping and interfittingend-portions assembled with each other to pivot about an axis extendingtransversely of the length of the machine, so that the several units ormembers of a machine may thereby articulate in an up-and-down direction.For such purpose, the body or block a of each unit is longitudinallyextended at one end in the provision of a trunnion l6 and at its otherend in the provision of a co-operable cup ll, the cup I! of one unitreceiving and interfitting with the trunnion lb of an adjoining unit.Each of the extended ends of the base-block a is provided with a pair ofprojecting vertically spaced stop abutments t, t, and the adjacent endfaces of each block a is provided with a projecting arcuate tongue tsized and positioned for limited swinging movement between the pair ofstop abutments t, t, on. the next adjoining block a so as to limit therelative rocking movement of the adjoining units. Each trunnion i6 isfurthermore provided with a peripheral semi-circular groove l6 whichregisters in opposing relation with a companion or corresponding grooveI l on cup H in the provision of a race or slot for receiving through anaperture or opening l3 formed for the purpose in the surrounding cup I!a series of balls or spheres I9 for securing the trunnion I8 and cup 11,and consequently also the two particular or adjoining units, togetherfor relative pivot or hinge movement in an up-an'd-down direction, thelocking spheres l9 being retained in their slot by means of a closureplug l9 thread-seated in the opening I 8 and the trunnion l6 and cup llfirmly securing such adjoining blocks a against separation or relativelongitudinal movement.

As will be evident, however, as seen in Figure 3, the yokes b, forsuccessful operation of the machine, should be permitted relativelongitudinal movement, as well as relative angular movement, withrespect to adjoining units. Hence, each yoke 22 at its left-hand end 20is approximately semicylindrical and of tubular formation incrosssection, as seen in Figures 11 and 12, to receive the right-handend 2! of a contiguous yoke b, which is also semi-cylindrical and oftubular formation in cross-section, but with an outside diametercorresponding to the inside diameter of yoke end-portion 29, the innerface of yoke endportion 20 being straight, longitudinally of the yoke,to accommodate lengthwise sliding movement of the two yoke end-portions20, 2 I, on each other. At and along its lower margins, each yokeend-portion 26 has inwardly turned flanges 22 opposing the lower margins23 of the associated yoke end-portion 2|, whereby the adjacent yokeend-portions are securely held against relative bodily movementvertically of their length. Upon its outer face, the yoke end-portion 2!is curved longitudinally of the yoke, as at 26, so that the assembledyoke-ends may readily incline, as Well as slide, lengthwise relativelyto each other as oocasion may require in a coal dislodging operation,spaced webs 25 formed in the one yoke-portion 20 in suitably spacedrelation to its end margin strengthening the yokes b of contiguousunits.

With the blocks a and yokes b of contiguous or successive unitsassembled and joined as described, in a coal dislodging operation theseveral blocks a and yokes b are free to take different angula positionswithin the limits permitted by the interengagement of the abutmenttongues t, t, and the stop tongue t, resulting in what may be referredto as limited articulation," and also the co-operable jack-formingcylinders c and pistons d of the several units may take differentexpanded positions, as best indicated in Figure 3, without undue stress,and, if expansion of one unit, such as A in Figure 3, results inyielding of the material or coal-body engaged by the machine, the thrustexerted by the pistons d of unit A will be transferred to and taken upby the adjacent unit C.

1 The hydraulic or other pressure fluid for actuating the jacks orcylinder-and-piston-power elements of the machine i supplied from a pumpor other suitable source of supply (not shown) and enters the machine atthe right-hand or forward end thereof through two tubular or pipemembers26, 21, of which pipe-member 26 conveys the fluid for the expandingaction of the machine and the tubular-member 21 conveys the fluid forthe contracting action of the machine. Tubes 26 and 27 are connected tothe front coupling block or member D, which has a trunnion l6corresponding to the trunnion l6 at the lefthand end of each unit bodya. Trunnion I6 is received in the cup I! at the front or right-hand endof the block a of unit A and is similarly retained in assembly therewithby spheres or balls it.

Each body or cylinder block a has conduits 28 and 29 extendingsubstantially throughout its length upon opposite sides of its cylindersc, the conduit or channel 28 having communication with the base orclosed end of each cylinder 0 of the unit, substantially as shown, forexpanding the several pistons, and the conduit or channel 29 havingcommunication with channels 29 in a selected piston or pistons d of theunit, substantially as shown, for contracting the several pistons.

Pressure fluid from tube 26 is delivered to bodyconduit 28 through achannel or passageway 39 in block or member D, as best seen in Figures17, 21, 22, and 23, the passageway or channel 30 extending inwardly anddownwardly from the tubenipple 2% and then transversely and downwardlyto an orifice at the end of trunnion l6 and on the axis of the latter inregistration with an orifice of a passageway or channel M in body aleading to and communicating with conduit 28. Pressure fluid from tube2? is delivered to the conduit 29 through a passageway 32 in block D,the passageway 32 extending inwardly and downwardly from the tube-nippleZll and then transversely beneath passageway 30 to a radial orifice intrunnion E6 to an annular chamber formed between trunnion l6 and anenlarged bore 33 in the cup ll of unit A, from which a passageway 34leads to and communicates with conduit 29.

Conduits 28 and 29 of one body-member a have communication with thecorresponding conduits in the adjacent body-member a through passagewaysor channels 30 3!, 32 and 34 disposed similarly to the two passageways30 and 32, as best seen in Figure 6, suitable preferably spring-pressedpacking 35 being interposed between the trunnion iS or IE and cup H forsealing the joint between such parts against escape of pressure fluid.

At its left-hand end, the rear unit B of the machine is in like mannercoupled with the endblock El and its pressure fluid passageways arepreferably closed by the coupling block E, which has a cup ill forreceiving the trunnion [6 of the end unit 13 and channels or passageways38 and t? for receiving the fiuid discharged from passageways 30 and 32respectively, the channels or passageways 3t and 3? being closed byclosure-plugs 38, which may be removed for at- 7 tachingtubular orpipe-members to this end of the machine.

In this connection, it may here be said that the machine as a whole mayinclude any selected number of units disposed in end-to-end relation andjoined so as to permit the blocks a and yokes b of the respective unitsto shift one relatively to the other in an up-and-down direction, theballs or spheres I9, l9, functioning not only as antifriction membersfor facilitating hinged movements or articulations of the respectiveunits, but in also retaining such units in such hinged or articulaterelation, the expanding actuating fluid entering the end unit A flowinginto and through the several cylinder-chambers c of the one unit andthen, in succession, through the several cylinder-chambers c of theremaining units of the machine and is drained back to the source ofsupply, as presently appears, the several pistons d of the several unitsbeing telescopically extended as the actuating fluid thus flows from onecylinder to the next cylinder of the particular unit, and thecontracting fluid entering the end unit A similarly flowing into andthrough the several pistons d of the one unit and then, in like manner,in succession, through the several pistons d of the remaining units ofthemachine and is in due course drained back to the source of supply andthe several pistons 01 contracted and their ,attached yokes b beingpositively returned to normal positions.

Accordingly, in use and operation, a kerf is suitably formed or producedin or adjacent the bottom level of the particular wall or body of coalbeing mined, and in suitably spaced relation upwardly from such kerf adesired plurality of suitably spaced holes of suitable depth are formedin the coal-body. One or more machines of our invention are thenlengthwise disposed in selected holes, with the several pistons d of therespective jacks or power elements thereof in contracted condition or inthe condition thereof illustrated in Figures 1, 2, and 7.

The tube or pipe 26 of the end block D of the particular machine issuitably connected with a source of fluid supply, and the fluid insuificient volume or amount led into the successive cylinders c of thesuccessive jacks of the several units of the machine. Hence, as thepistons d of a unit A are thus successively elongated or extended, thatportion of the coal-wall intermediate said kerf and said several "holesis, under the relatively great pressure exerted upon the coal-wall orbody by the elongating pistons d, successively disrupted and dislodgedand its removal from the mine thereby conveniently facilitated.

In such a dislodging operation, the pivot or hinged coupling between theseveral blocks a and also the sliding connection between the severalyokes b of the several units of'a machine-readily permit a hingedlyshifting movement in graduated increasing amount from the base a of eachunit to its yoke b, comparable to the greater movement of the rim of awheel as compared to its hub, in an up-and-down direction betweenltherespective units of the machine, with the result that, as the coalshifts under the disrupting pressure exerted thereon by the hoods ryokes b under the power exerted by the successively expanding pistons dof each successive lack, any

one or more of the units of the machine may readily hingedly moveobliquely in an up-anddown direction with respect to the'remainingunits,ias--indicated in Figure 3. In all such movements, the'outwardmovement of the pistons -d is limited and controlled by the companionshoul tier-couplets 3'-4 and 2-4 and, also, the blocks a and yokes b ofthe several units may rock or shift with the breakingcoal. Hence themachine augments and facilitates shifting movement of the dislodgedcoal, and at the same time the relative flexibility of the several unitsand their several jacks and yokes eliminates and obviates breaking ofthe machine in or by shifting movement of the disrupted coal, therespective arcuate' and, at the same time, motive or pressure fluid issupplied to the selected piston or pistons d through conduits 29 and thedescribed communicating ways or channels for'positively returning theseveral pistons d andattached yokes b to normal contracted condition,when the machine may be easily removed for successive operations; Inthis connection, it may be observed that the several yokes or hoods bpivotally shift with, and slidably move relatively to, their respectiveunits, as well as also shift vertically, as it may besaid, by and withthe piston-rods 6 relatively to the blocks a during their coaldislodging travel and thus function in exerting upon, and distributivelythrough a relatively greater area of, the engaged coal the breaking ordislodging pressure developed by the several pistons (land insubsequently facilitating removal of the unit'when the several pistonsthereof reoede tonormal cone,

tracted condition. 7 1

As depicted in Figures 26 to 29, both inclusive, a modifiedform of hoodhas been found by test to, be desirable under certain conditions,particularly when extreme difierences in the angularity of adjacenthoods occurs. 7

In this embodiment, the inwardlyturned flanges 22 are dispensed with andthe end-portion 20 of the hood I) is cut away at its lower left handextremity and curved or rounded,=as shown at 2B". The opposite end 2! ofhood I) is provided with outwardly turned flanges 2| at its lowerright-hand extremity; In all other'respects, the hoods b and b aresimilar.

In use, the rounded portions 28 of one hood b slidably engage andinterfit with the outwardly turned flanges 2!" of an adjacenthood. Thehoodjoint thus formed is similar to ,thatof the main formgand functionsin the same mannet, but permits adjacent hoods to assumetions ofrelatively',.greater angularity.

Preferably each' trunnion-cup connection is suitably equipped with asealing gasket 39, as best seen inFigure 6', and it is to be understoodthat changesand modifications in the form, construction, arrangement,and combination of the several parts of the machine may be made andsubstituted for those herein shown and; de- H posiwith respect to thecylinders, each piston having an arcuate upper face, pillow-blocks eachhaving a matching-arcuate under face disposed loosely I in engagingrelation upon the upper faces of the respective pistons, and anelongated rigid yoke having connection with the several pillow-blocksand being shiftable by and with the pistons throughout their stroke.

2. In a mining-machine, a jack-unit including an elongated block, aseries of spaced paral having a matching arcuate under face disposedloosely in engaging relation upon the upper faces of the respectivepistons, and an elongated rigid yoke having slidable connection with theseveral pillow-blocks, the yoke being shiftable by and with the pistonsthroughout their stroke and the several pistons being tiltablerelatively to the pillow-blocks.

3. In a mining-machine, a jack-unit including an elongated block, aseries of spaced parallel cylinders in the block, pistons reciprocablein and with respect to the cylinders, each piston comprisingtelescopically co-operable members and each having an upper face ofarcuate conblocks each having a matching arcuate under face disposedloosely in engaging relation upon the upper faces of the respectivepistons, an elongated rigid yoke of arcuate contour in crosssectionhaving a slidable connection at its central under face with the severalpillow-blocks and umbrella-wise disposed over the several pistons, andmeans for limiting the slidable disposition of the yoke with relation tothe pillowblocks, the yoke being shiftable by and with the pistonsthroughout their stroke and the several pistons being tiltablerelatively to the pillowblocks in the longitudinal direction of themachine.

4. In a mining-machine, a series of jack-units connected one with theother for articulation, each unit comprising a connected series ofspaced parallel co-operable cylinders and reciprocatory pistons, aplurality of yokes one for each unit, each respective yoke havinglongitudinally rockable connection with the several pistons of such unitfor shiftable movement by and with the pistons relatively to therespective cylinders, said yokes being respectively interfitted at theirends so as to pivot and slide relative to each other, the

several units having communication one with the other for fluid pressureflow, and fluid pressure means for reciprocating the several pistons andtheir respectively connected yokes relatively to the respectivecylinders.

5. In a mining-machine, a pair of jack-units each comprising anelongated block, a series of spaced parallel cylinders in the block,pistons reciprocable in and with respect to the cylinders, and a yokedisposed over andhaving longitudinally rockable connection with theseveral pistons for movement by and with the pistons during theirreciprocations, said yokes being respectively interfltted at their endsso as to pivot and slide relative to each other, means joining theblocks endwise together for articulation, and fluid pressure means forreciprocating the several pistons of the respective units and theirrespectively connected yokes relatively to the respective blocks.

6. In a, mining-machine, a pair of jack-units '10 each comprising ablock, a series of spaced parallel cylinders in the block, pistonsreciprocable in and with respect to the cylinders, and a yoke disposedover and having longitudinally rockable connection with the pistons formovement by and with the pistons during their reciprocations, meanscomprising extensions on the blocks and interfitting extensions on theyokes for joining said yokes endwise together for slidable and pivotalmovement relative to each other, and fluid pressure means forreciprocating the several pistons of the respective units and theirrespectively connected yokes relatively to the respective blocks.

'7. In a mining-machine, a pair of jack-units each comprising anelongated block, a series of spaced parallel cylinders in the block,pistons reciprocable in and with respect to the cylinders, and a yokedisposed over and having longitudinally rockable connection with theseveral pistons for movement by and with the pistons during theirreciprocations, means hingedly joining said blocks endwise together forunit articulation, and fluid pressure means for reciprocating theseveral pistons of the respective units and their connected yokesrelatively to the respective blocks, the yokes of the units havinglongitudinal extensions loosely interfitting for relative movement onblock articulation.

8. In a mining-machine, a pair of jack-units each comprising anelongated block, a series of spaced parallel cylinders in the block,pistons reciprocable in and with respect to the cylinders, and a yokedisposed over and having longitudinally rockable connection with theseveral pistons for movement by and with the pistons during theirreciprocations, means pivotally joining the blocks endwise together,said yokes of the units having longitudinal extensions looselyinterfitting for relative slidable movement lengthwise and angularlywith respect to each other, and fluid pressure means for reciprocatingthe several pistons of the respective units and their connected yokesrelatively to the respective blocks.

9. In a mining-machine, a pair of power-units,

F each unit including a co-operable cylinder and a reciprocatory piston,means joining the cylinders for unit articulation, pressure-pads mountedon and movable with the respective pistons, said pads being spaced onefrom the other, and means comprising interfitting extensions on the padsfor forming with the pads a substantially continuous articulatedpressure-hood.

10. A mining-machine comprising a plurality of longitudinally alignedhydraulic rams hingedly connected to each other in a successive series,a

pair of spaced abutments upon one end of each ram, and a projectingabutment upon the opposed end of the next adjacent ram for limitedmovement between said spaced abutments.

11. A mining-machine comprising a plurality of power units, each powerunit consisting of a base-block having a plurality of cylinders andreciprocable pistons mounted therein, said pistons being provided withan overlying hood operably mounted thereon, each of said base-blocksbeing hingedly connected at its ends to adjoining baseblocks, a pair ofspaced stop-members on each base-block, and a tongue on each base-blocksized and positioned for operative dispostion between the pair oftongues upon the next adjoining baseblock for limiting the hingedmovement of such base-blocks relatively to each other.

12. A mining machine including a plurality of connected base memberseach having a series of spaced parallel co-operable cylinders andreciprooatory pistons, and a :hood mounted -upon and disposed over eachof the several -Series -of :pistohe, each hoodbeing-rockably mountedupon the upper :ends of --such pistons for-movementlinto arigularposition in a direction longitudinally-0f "themachine and beingsubstantially limited to afigillar movement in such longitudinaldirection, :saidfhoods being endwise engaged for rockable movementwithrespect toeach other.

RICHARD T. HAIR. CHARLES F. BALL.

I v .TREEERENGES CITED "f lhe o w. ne eferen e a eco .d n the .11 9 ofthis patent:

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